Differential driving mechanism.



F. N. ROEHRICH.

Patented A r. 18, 1916.

2 SHEETS-SHEET I.

Q, ILL. 6

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DIFFERENTIAL DRIVING MECHANISM.

APPLICATION FILED APR-25,1912. RENEWED JUNE 1, 19x4.

LlfiQU'YQ. Patented Apr. 18, 1916.

2 SHEETS-SHEET 2- Wbtweooeo J1 1WD lt li llfilil.

FRANK N. ROEHRICH, OF JERSEY CITY, NEW JERSEY.

DIFFERENTIAL DRIVING: MECHANISM.

Application filed April 25, 1912, Serial No. 693,073. Renewed June 1,191 1.

To all whom it may concern:

Be it known that I, FRANK N. RoEHRIoH, a citizen of the United States,residing at Jersey City, in the county of Hudson and State of NewJersey, have invented certain new and useful Improvements inDifierential Driving Mechanism, of which the following is aspecification.

This invention relates to differential driving mechanism adapted foruse, more especially, in connection with the axle shafts of motor drivenvehicles, such, for example, as automobiles.

The object of my invention is to provide a mechanism of the kindreferred to which shall combine, in its construction and operation, themerits of simplicity, cheapness, durability and efiiciency.

To this end, the invention, as generally stated, comprehends variousnovel features of construction and combinations of parts which will behereinafter described and claimed.

The particular form of embodiment of the invention herein selected forillustration consists in the provision between the elements to bedriven, such, for example, as the axle shafts of a pair of tractionwheels, of a rotatable head equipped with a pair of intermeshing spurwheels which are mounted with spaced relation to the inner ends of theshafts, crank and link connections between one of the gear wheels andone of the shafts, and similar though oppositely-disposed connectionsbetween the other gear wheel and shaft, as will presently appear.

While I shall hereinafter point out in detail the structural features ofthe illustrative mechanism above indicated it is to be understood thatmy invention is not re stricted to the details to which reference may bemade, as the structure may be modified in many respects withoutdeparture from the fair spirit of the invention.

In the drawings Figure 1 is a transverse horizontal section ofdifferential driving mechanism embodying the preferred form of myinvention, showing a portion of a traction wheel on one of the drivenshaft elements. Fig. 2 is a transverse vertical section, as on the line22 of Fig. 1. Fig. 3 is a transverse horizontal section, enlarged,through the rotary head and its contained elements, the gear ring on thehead being omitted.

,t, 2 designate two elements to be driven,

Specification of Letters Patent.

Patented Apr. 1%, 1916.

Serial 11.0. 842,253.

the same being illustrated as the two alining axle shafts of anautomobile. 3 is a portion of a traction wheel carried by one of saidshafts, and 4 is a cylindrical casing bolted or otherwise secured to theinner ends of the fixed tubular casings 5 for the shafts, these partsbeing of any usual or approved construction.

Within the casing is mounted axially of the shafts a rotary head A whichis equipped at or near one of its sides with a bevel gear ring 6 inengagement with a bevel gear wheel 7 on the inner end of the powerdriven shaft 8, such inner end having its bearing in the wall of thecasing 4;. Thus the head is bodily rotated on'its axis by actuation ofthe shaft 8 from a suitable source of power. This head in its preferredconstruction embodies a rectangular skeleton frame composed of thespaced side and end members 9, 10 respectively. The side membersareprovided with suitably-disposed hubs 11 which are journaled,preferably upon ball bearings 12, (Fig. 1) in the respective sides ofthe casing 1, the inner ends of the axle shafts extending axiallythrough the hubs into the interior of the head as shown. The ends of theframe, adjacent one side thereof, are provided with a flanged ring 13 towhich is bolted or otherwise secured the bevel gear ring 6. Journaled insuitable bearings 14: in the respective sides 9 of the frame are twoinwardly extending stub shafts 15 which are disposed at diametricallyopposite points equidistant from the axis of the head. On the inner endsof these shafts are two crank members 16 constituted in the presentinstance by two similar inter-meshing gear wheels which are locatedmidway between the sides of the head, or nearly so.

On the inner ends of the axle shafts are fixed crank disks 17 which areconnected with the respective gear wheels 16 by means oftwooppositely-disposed sets of lateral link' connections 18. In the presentcase there are three/links for each gear wheel and its complementarycrank disk, which links, being of corresponding length, are pivotallyconnected at one end thereof to the disk, at equidistant points from thecenter of the latter, and at the other end to the gear wheel atequidistant points from its center; the pivotal. points of the links attheir respective ends being such that the approaching ends will escapeeach other during the relative rotation. of the gear wheel and crankdisk. Thus if the crank disk be free to rotate and its complementarygear wheel be rotated on its own axis uniform and positive transmissionof motion from the rotating gear wheel to its connected shaft sectionwill be effected irrespective of the position which the axis of the saidgear wheel may occupy in a circular path described from the axis of theshaft. If, on the other hand, the crank disk be held against rotation,and its complementary gear wheel be bodily revolved about the axis ofthe head, the link connections between the gear wheel and the relativelyfixed crank disk will effect the relative rotation of the gear wheelsimilarly to the planet motion.

From the foregoing it will be seen that the head A through its gearconnection with the power shaft 8 is continuously rotated, therebybodily rotating as a unit the gear wheels and their connected shafts 1,2 in the's'ame direction if the two shafts be equally free to turn or besubjected to corresponding traction conditions,.as, for example, whenthe vehicle is traveling'in a direct path; or, in other words, theopposing gear wheels by virtue of their respective link and crankconnections with the two shafts normally look the shafts axiallyto thehead. If, however, during the rotation of the'head one of the shafts(as 1) be held or restrained, (as, for example, when the vehicle isturning a curve) the link connections between that shaft and the gearwheel will effect and permit the independent rotation of the latter asthe wheel is revolved by, and around the Such rotating gear wheel willin turn rotate the gear wheel in mesh therewith and the latter throughits link and crank connectionswith the shaft (as 2) will positivelyrotate the latter; or, in other words, when one of the shafts is held orrestrained the rotating head transmits its motion through the relativelyrotating gear wheels to the link and crank connections of the othershaft. The moment the abnormal resistance is removed from the restrainedshaft, or the two shafts are subjected to equal force, the said shaftswill be locked to the head through the counteraction of the respectivelink and crank connections and gear wheels, and thus be concurrentlyrotated axially with the head, as above described.

I claim 1. In differential driving mechanism, the combination with twodriven elements, of a rotary support, means for actuating said wheel ofa sun-and-planet Copies of this patent may be obtained for five centseach, by addressing the axis of, the head.

support, a crank member on one of said driven elements, a complementarycrank member therefor mounted on the support, link connection betweensaid crank members, a crank member on the other driven element, acomplementary crank member therefor mounted on the support, linkconnection between the latter two crank members, and operativeconnection between the two crank members mounted on the support.

2. In differential driving mechanism, the combination with drivenelements, of an interposed rotary support, means for actuating saidsupport, inter-meshing gear wheels independently mounted on saidsupport, crank and link connections between one of said driven elementsand one of said gear wheels, and crank and link connections between theother driven element and gear wheel.

3. In differential driving mechanism, the combination with drivenelements, of an interposed rotatable frame in axial alinemcnt with saidelements, means for actuating said frame, intermeshing gear wheelsindependently mounted on said frame, crank and link connections betweenone of said driven elements and one of said gear wheels, and crank andlink connections between the other driven element and gear wheel.

4. In differential driving mechanism, the combination with drivenelements, of an interposed rotatable frame in axial alinement with saidelements, a gear ring on said frame, a drive shaft, a gear thereonengaging the gear ring, intermeshing gear wheels independently mountedon said frame, crank and link connections between one of said drivenelements and one of said gear wheels, and crank and link connectionsbetween the other driven element and gear wheel.

5. In differential driving mechanism, the combination of two drivenshafts, of a rotatable frame into which extend the inner ends of saidshafts, means for rotating said frame, intermeshing gear wheelsindependently mounted. on said frame at diametrically opposite pointsequidistant from the axis of rotation of the frame, crank members-on theinner ends of the shafts, a plurality of spaced link connections betweenone of said gear wheels and one of said crank members, and a pluralityof spaced link connections between the other gear wheel and crankmember.

FRANK N. ROEHRICH.

WVitnesses:

JoHN E. PRAGER, A. Woman GIBBS.

"Commissioner of Patents,

Washington. D. 0.

